There's an upside and a downside to having a martini before a meal. On one hand it's the equivalent of a reveille, letting the stomach know that, hurrah, we're not having frozen pizza for once. On the other hand, a martini's alcohol content may make you forget to appreciate the food at all.

This would be a bit of a waste tonight because I've come to Gillray's, a new steak restaurant in the old London County Hall building. A 450g porterhouse steak costs £36 and the meat has, I'm assured by chef Gareth Bowen, spent two years eating only the best pasture, before shuffling off in the direction of what he refers to, with a respectfully lowered voice, as its "final destination".

But, at Gillray's, the gin is almost as important as steak and their menu trumpets the fact that the two can be the perfect partnership. "There are certain gins that are very strong in the flavour of juniper," explains bar manager Karina Elias, "and juniper and beef is a great marriage."

That's why I'm planning to not just start with a martini, but to ignore the wine menu and stick with gin for the whole meal. Gillray's is one of a number of establishments pushing the idea of a "cocktail sommelier." The Assagetti restaurant in Piccadilly, for example, encourages diners to try its mojito sbagliato with fish and there have been similar attempts to entice customers away from the wine list at US restaurants such as PS7 in Washington DC and the newly opened Booker and Dax in New York.

The waiter at Gillray's suggests I try an aston webb collins with my steak: "pomegranate and passion fruit seeds muddled with mint and sugar, shaken with Tanqueray gin." It is nice enough but too fruity to bring out the best of the wonderfully flavoursome meat. I think my mistake was in requesting something not too alcoholic. Despite the pleasantness of both the food and the drink, I'm not sure they're ready to get hitched yet, even if, at Gillray's, a cocktail at £10 is only about £3 more than a glass of merlot.

However, the march of cocktails from bars into restaurants won't stop here. The next day I visit cocktail maker Tony Conigliaro's laboratory, where he's working with Belgian food scientist Bernard Lahousse to create what they're hoping will be the inspiration for a food and cocktail pairing menu at his bar this summer.

The first results are on the table in front of me. A plate of puréed aubergine, raisins, black olive, dry ham, lime zest, pickled walnuts and tahoon cress and, next to it, a glass of Conigliaro's woodland martini. The theory is that the drink and the odd, experimental dish share what they call a "flavour profile" and that, following a mouthful of one with a mouthful of the other, will result in both becoming more than the sum of their parts.

Lahousse has analysed over a thousand different ingredients, breaking them down into their constituent aromas, and he says that, as a rule, you'll find that foods or drinks which go well together share some molecular kinship. This works, he claims, even when you reverse-engineer recipes by the likes of Escoffier or time-honoured cocktails such as the mojito. "If you divide rum into its aromas," he says, "you find that in one part you can smell mint. If combinations work, most of the time there is a scientific explanation."

The woodland martini is made of gin, amontillado sherry and "woodland bitters". It does, indeed, go well with the earthy flavours that Lahousse has put together. More importantly, though, using their techniques, a mixologist ought to be able to create a cocktail to go with almost any dish. "It's easier to fit a cocktail to a dish than it is a glass of wine because you have more tools and many more flavours to play with," says Conigliaro.

So, in theory, with the right information, you could take the ingredients of a frozen pizza and then mix up a cocktail to match. Prime steak, however, will surely always be happier with a nice glass of wine.